The applicant of the present invention proposed an apparatus with which at least two fluids are mixed and stirred between processing surfaces capable of approaching to and separating from each other and rotating relative to the other, whereby carrying out, for example, reaction and crystallization (Patent Document 1 and Patent Document 2). An apparatus like this has solved a problem such as clogging of a micro flow path by a reaction product and necessity of large supply pressure as a flow path becomes narrower, which have been problems of a micro reactor or a micro mixer shown in Patent Document 3 or Patent Document 4.
In the apparatus as described in Patent Document 1 and Patent Document 2, a first fluid as the first fluid is introduced between processing surfaces capable of approaching to and separating from and rotating relative to the other and a second fluid as the second fluid is introduced between the processing surfaces from a separate flow path having an opening leading to a space between the processing surfaces, the said flow path being independent of a flow path through which the first fluid is introduced, whereby the first and second fluids are mixed and stirred between the processing surfaces. By incorporating a material to be reacted into the first fluid or the second fluid or both of them, reaction, crystallization, and so on, are effected between the processing surfaces.    Patent Document 1: JP-A 2004-49957    Patent Document 2: WO2009/8394    Patent Document 3: JP-A 2006-104448    Patent Document 4: JP-A 2003-159696